Is Alaska Sinking?

Is Alaska Sinking?
By Sarah Ives
National Geographic Kids News
September 01, 2004
Houses collapse. Trees fall over. Giant potholes form in the ground. Could Alaska be sinking?
That's what some villagers in Alaska have been asking themselves recently—and scientists think they know why. Warmer temperatures may be causing Alaska's frozen ground to thaw.
About 85 percent of Alaska's land surface has permafrost. Permafrost is a part of the ground that is always frozen.
"In many areas of the [United States], the moisture in the ground freezes during the winter," scientist Tom Osterkamp said. He has studied Alaska's permafrost for more than 25 years. "The ground that doesn't thaw during the summer is called permafrost, a [combination] of the words, 'permanent frost.'"
Permafrost supports the ground above it—including trees, houses, and roads. If the permafrost thaws, the ground can collapse.
"When big ice pieces in permafrost, which can be as large as houses, melt, the ground collapses and big holes form. Where there is a house or a road where the holes form, the house collapses too, and there are big potholes in the road," Gunter Weller of the Cooperative Institute for Arctic Research said.
But why is the permafrost thawing?
Some scientists say that human-caused pollution is leading to global warming. And most scientists, including Osterkamp and Weller, agree that Alaska has been getting warmer. They say that the warmer temperature is causing permafrost to thaw in some areas.
The thawing permafrost can cause problems for people, plants, and animals.
"[The collapsing] is a problem in the villages in Alaska which are built on permafrost, and some of them may have to move to safer ground, where there is no permafrost," Weller said.
The Alaskan town of Glennallen saw its old post office collapse. And, according to James Walters, a permafrost expert at the University of Northern Iowa, house-moving companies have been very busy.
One company's motto is, "Move it or lose it," Walters said.
Animals are affected by the melting too.
"Melting permafrost can also destroy trees and forests," Weller said. "When holes in the ground form, trees fall into them and die. This could turn a forest into a meadow, and animals which need the forest will have to move elsewhere."
Osterkamp says that the melting could cause "severe problems."
Weller agrees: "This could take hundreds of years, but in the end Alaska will look quite different from what it looks [like] now."
Talk about a chilling theory!